ACTG 320: The purpose of this study is to determine both the safety and effectiveness of indinavir (IDV) in combination with zidovudine (ZDV) and lamivudine (3TC) in persons infected with HIV, and to determine if this drug combination delays the time to development of an AIDS defining illness and/or improves survival when compared to ZDV/3TC. The primary endpoint of the study will be clinical disease progression (AIDS defining event or death), whichever occurs first. This is a phase III study with a total subject base of 1750 with approximately 40 subjects to be enrolled locally. Subjects will be followed for 48 weeks following the last patient enrollment for a duration of 2 years.